IMPAIRMENT OF IODOTHYRONINE 5'-DEIODINASE ACTIVITY IN BROWN ADIPOSE-TISSUE AND ITS ACUTE STIMULATION BY COLD IN SELENIUM DEFICIENCY

John Arthur, Fergus Nicol, G J BECKETT, P TRAYHURN

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

The activity of the type II iodothyronine 5'-deiodinase enzyme in brown adipose tissue has been examined in rats fed a selenium-deficient diet. Iodothyronine 5'-deiodinase activity was threefold lower in brown adipose tissue of deficient rats than in control animals. The activity of glutathione peroxidase, a biochemical index of selenium deficiency, was also greatly decreased in deficient animals. Cytochrome oxidase activity in brown fat was, however, unaltered by selenium deficiency. Acute exposure to cold (4-degrees-C for 18 h) resulted in a substantial increase in iodothyronine 5'-deiodinase activity in brown adipose tissue of control rats, but the stimulatory effect of cold was attenuated in selenium-deficient animals. These results support the concept that the iodothyronine 5'-deiodinases are selenium-dependent enzymes, and indicate that the thermogenic response to cold may be impaired in selenium deficiency.

Original languageEnglish
Pages (from-to)782-785
Number of pages4
JournalCanadian Journal of Physiology and Pharmacology
Volume69
Issue number6
Publication statusPublished - Jun 1991

Keywords

  • IODOTHYRONINE 5'-DEIODINASE
  • GLUTATHIONE PEROXIDASE
  • SELENIUM DEFICIENCY
  • BROWN ADIPOSE TISSUE
  • COLD EXPOSURE
  • UNCOUPLING PROTEIN
  • RAT-LIVER
  • TRIIODOTHYRONINE
  • THYROXINE
  • INHIBITION
  • NOREPINEPHRINE

Cite this